This invention relates to the hydraulic oil-based technology of a capsule chemistry sample liquid analysis system for the automated clinical analysis of samples of human biological fluids.
Capsule chemistry technology utilizes an oil-based segmented-flow technique combined with a noninvasive method to combine and mix each sample aliquot with the required reagents for the specific analytical test or method. This non-invasive technology is achieved by sophisticated microhydraulics, and requires no intrusion into the reaction pathway and no moving parts.
The entire analytical process, from sampling to readout, occurs in a single capillary tube referred to as the analytical line or conduit. A typical automated capsule chemistry liquid analysis system is described in U.S. Pat. No. 5,268,147 to Zabetakis et al, the disclosure of which is incorporated by reference herein.
An important part of the analytical line is an enlarged cross-sectional area known as the “vanish zone” which operates in the manner of an expanding flotation zone to combine liquid segments positioned on each side of an air segment.
Important developments in capsule chemistry technology include refinements of the geometrical dimensions of the analytical line and vanish zone; the volumes of reagent capsules; the reaction chemistry; and the physical-chemical properties of reagents, buffer, oil, probe and analytical line. Despite these refinements, hydraulic failures in the analytical line occur. These hydraulic failures can lead to anomalous analytical results due to carry-over or cross-contamination and are detected by the automated clinical analyzer system. The frequency of these hydraulic failures varies, depending on the system parameters. Hydraulic failures require in many cases the repetition of the analysis and therefore reduce the cost-effectiveness of the automated clinical analytical system.